Hydrocarbon oil conversion



March 27, l 934. J w bswgfi-n- 1,952,692

HYDROCARBON 01L CONVERSION 2 Sheets-Sheet A 4 i i 4 mmumzun 00 INVENTOR JAMES M. WADSWORTH 1 05 AT CSRNEY March 27, 1934. J, M. WADSWOR'IY'H 1,952,692

HYDROCARBON OIL CONVERS ION Filed Aug. 4, 1930 2 Sheets-Sheet 2 CONDENSER EvAPoRATo INVENTOR JAMES M. WADSWORTH ATTORNEY Patented Mar 27, 1934 PATENT OFFICE HYDROCARBON OIL CONVERSION James M. Wadsworth, Tulsa, Okla, assignor to Universal Oil Products Company, Chicago, 11]., a corporation of South Dakota Application August 4, 1930, Serial No. 472,773

3 Claims. (Cl. 196-47) This invention relates to improvements in the art of converting higher boiling hydrocarbons to lower boiling point hydrocarbons, and refers in a a specific embodiment to a method for recovering valuable low boiling products from the cracking process, as well as accomplishingother desirable objects. 1

In cracking or conversion processes generally where higher boiling hydrocarbons are converted to those of lower boiling range residual oils are produced in many operations which are marketed directly or are blended to meet market specifications. Suitable blending materials for thinning heavy residual oils are intermediate fractions of higher boiling range than motor fuel, for example, so-called pressure distillate bottoms. Other oils of intermediate boiling point range are also used for thinning heavy viscous residual oil in their preparation for marketing.

These oils of intermediate boiling range are also generally suitable for the removal of low boiling gasoline components usually present in gases from the cracking process; by contacting or scrubbing the gases with the aforementioned oils and subsequently removing the absorbed gasoline-like components by distillation. My invention combines these processes in a new and useful manner.

In the steps or improvements comprising my invention the, uncondensible gases from the cracking process containing motor fuel hydrocarbons are directed to some form of tower or scrubbing means whereby the condensable hydrocarbons are removed by an oil of absorptive qualities, for example, pressure distillate bottoms. The enriched absorption or blending oil is mixed with the hot residual oil withdrawn from the cracking process, the lower boiling hydrocarbons being vaporized by the heat of the residual or unvaporized oil from the cracking process and subsequently condensed and collected. Steam or other suitablematerials can be injected into the body of the admixed oils or into the vessel containing same so as to completely strip the mixed oil of low boiling constituents and thereby impart to it the desired characteristics as to flash and fire test. a

The accompanying drawings, Figs. 1 audit, not drawn to scale, illustrate in a diagrammatic manner the improvements comprising my invention as applied to a cracking process well known -in the industry.

Hydrocarbon oil is directed to the process through line 1 and valve 2. passing to pump 3 which pumps this oil through line 4 leading to line5, from which the oil may be directed through valve 6 to the dephlegmator I, where this oil is preheated in direct or indirect heat interchange with flashed distillation vapors. Any desired portion of the hydrocarbon oil entering line 5 may flow through line 8 and valve 9 intoline 18 where it mixes with oil flowing to the heating element of the process and/or it may be directed into line 10, regulated by valve 11, leading to dephlegmator 12. Flashed and condensed vapors, together with hydrocarbon oil introduced to dephlegmator '7, flow through line 13 and valve 14 to pump 15 which pumps this oil through line 16 from which it may be diverted in part or in whole through line 48, regulated by valve 49, into line a which 7 directs the oil into the stream of oil flowing to the heating element and/ or through valve 1'? into line 10 leading to dephlegmator 12 where oils introduced through line 10 come in heat interchange with the vapors and serve to condense partially converted hydrocarbons. Condensed partially converted hydrocarbons, together with oil introduced, flow through line 18 and valve 19 to pump 20 which pumps this mixture of oils through line 21 and valve 22 to heat element 23 located in furnace 24. p

The heated products leaving heating element, 23 flow through line 25, regulated by valve 26, into reaction chamber 27 where separation 01 vapor and non-vaporized products is also effected. Non-vaporized oil is withdrawn through line 28, regulated by valve 29, and is subjected to treatment, as will be later described. vaporized products leave reaction chamber 27 through line 30, regulated by valve 31, and enter dephlegmator 12 where the vapors are subjected to heat interchange as partially described above. Vapors and gases from dephlegmator 12 flow through line 32 and valve 33 to condenser 34 and the cooled products flow through line 35 and valve 36 to high pressure receiver 37 where separation of the liquid and gaseous products is efiected. Gaseous products are removed through line 38, regulated by valve 39, and flow to header line 40 100 for distribution as will be later described. Liquid products flow through line 41, regulated by valve 42, to the low pressure receiver 43, and are there disposed as will be later described. Obviously the gaseous products can pass from receiver 37 105 to receiver 43 by closing valve 39 in line 38. Any desired portion of the oil in receiver 37 may be directed through line 43' and valve 44 to pump 45 which pumps this oil through line 46 and valve 47 to the top of dephlegmator 12, so as to regu- 110 acter of the overhead product.

Any portion of the non-vaporized oil removed from reaction chamber 27may be directed into line 50 by regulation of valve 51, which directs this oil through valve 52 into line 53 leading to storage or through line 108, regulated by valve 109, to a separate cooler (not shown) and thence to storage. The bulk of the non-vaporized oil withdrawn from reaction chamber 27 through line 28 is preferably directed through line 54, regulated by valve 55, into the flash distillation chamber 56 where fresh distillation takes place due to the sensible heat of the non-vaporized oil and a reduction in pressure. The non-vaporized oil from the flash distilling chamber flows through line 53, regulated by valve 57, and is further utilized as will be later described. Vapors from flash distillation chamber 56 pass through line 58 and valve 59 into dephlegmator 7 where heavier vapors are condensed as above described. Gasoline containing vapors leave dephlegmator 7 through line 60, flowing through valve 61 to condenser 62, and the cooled products flow through line 63 and valve 64 into receiver 65 where separation of liquid and gaseous products is efiected. Gaseous products are removed through line 66, regulated by valve 67, and are directed to the header line 40. Gasoline containing distillate is removed through line 70, regulated by valve 71, and gases rich in light motor fuel fractions are directed through line 72, regulated by valve 73, to the bottom of absorber 74.

An absorption oil, preferably pressure distillate bottoms obtained by redistillation of the gasoline containing hydrocarbons obtained in the process, is directed through line 110 and valve 111 to pump 112 which pumps this oil through line 114 and valve 113 to the top of absorber 74 where it flows downward and counter-current to the ascending gases absorbing condensible, light hydrocarbon vapors. The stripped gas leaves absorber 74 through line 75 and flows through valve 76 into header line 40. The absorption oil leaves the bottom of absorber 74 through line 77, regulated by valve 78, and flows into evaporator 79, or the absorber oil may flow into line 80 and through valve 81 into line 82 leading to evaporator 79. The heat is supplied in evaporator '79 by flashed residuum, i. e., the non-vaporized oil withdrawn from .fiash distillation chamber 56 through line 53 anddirected through line 82, regulated by valve 83, to the evaporator '79. A mixture of flashed residuum and spent absorption oil is removed through line 84 and flows through valve 85 to pump 86 which pumps this oil through line 87 and valve 88 into line 53. Vapors and gases from the evaporator flow through line 89 and valve 90 to the condenser 91 from which the cooled products pass through line 92 and valve 93 to receiver 94 where separation of the light hydrocarbon product is separated from gaseous products. The condensate is removed through line 95, regulated by valve 96, and the gases are removed through line 97, regulated by valve 98, and may be pumped by pump 99 through line 100, regulated by valve 101, into the gas header 40.

Uncondensable gases in the header line 40 received through-lines66, and 100 may be directed through valve 102 to the burners supplying heat in furnace 24, or may be directed through valve 108 to storage, the field burners, or to other suitable disposal. Flashed residuum flowing through line 53 and not directed through line 82 late the temperature and to control the char-- to evaporator 79 may flow through valve 104 and mix with oil leaving the evaporator 79 and flow through valve 105 to a cooler (not shown) and then to storage, or may flow through line 106, regulated by valve 107, to a separate cooler (not shown) and to storage.

As a specific example of the improvements comprising my invention in connection with the cracking process above illustrated and described, a mid-continent topped crude oil of approximately 26-28 A. P. I. gravity is directed to the process and after preheating and admixture with partially converted hydrocarbons is directed to heating element 23 where a temperature of approximately 900 F. and a pressure of approximately 225 pounds is maintained, converted hydrocarbon vapors formed in reaction chamber 27 are dephlegmated and treated substantially as above described. The pressure distillate removed from receiver 37 Where the pressure is approximately 200 pounds per square inch, is removed to low pressure receiver 43 where a pressure of approximately 35 pounds per square inch is maintained, and the gases released from the pressure distillate-and rich in motor fuel hydrocarbons are directed to absorber 74 through line 72. Nonvaporized residual oil is withdrawn from reaction chamber 27 through line 28, regulated by valve 29, and directed toflash distillation chamber 56 where the pressure on this oil is reduced from approximately 225 pounds to approximately 50-60 pounds per square inch, and the oil is flash distilled, utilizing its latent heat content. The vapors therefrom are treated substantially as described above, and the non-vaporized residual oil, which has a viscosity of approximately 800 seconds Furol at 122 F., is directed throughline 53 into line 82 where it mixes with enriched pressure distillate bottoms from absorber '74 and passes to evaporator 79. The pressure distillate bottoms pumped to absorber 74 amount to approximately 10 percent. of the residuum directed to the evaporator 79 and the final, blended fuel oil product removed from evaporator 79 has a viscosity of approximately 220 seconds Furol at 122 F. The motor fuel distillate collected and removed from receiver 94 represents approximately two gallons per 1000 cubic feet of gas directed to absorber 74.

The above illustrations of the improvements in cracking processes should not be construed as a limitation upon the broad spirit and scope of the invention.

I claim as my invention:

1. In a hydrocarbon oil cracking operation wherein there is produced gasoline incondensible gases and flash residuum, the method whichcomprises separating the gases from the gasoline and scrubbing the same with an absorption oil to remove light condensible fractions therefrom, removing the flash residuum from the cracking operation, mixing the enriched absorption oil with a quantity of the residuum sufllclent in amount and temperature to vaporize the absorbed condensible fractions while retaining a substantial portion of the absorption oil in admixture with the residuum, and recovering the resultant blend of absorption oil and residuum as a product of the process.

2. In a hydrocarbon oil cracking operation wherein there is produced flash residuum and a mixture of pressure distillate and incondensible gases, the method which comprises separating the gases from the pressure distillate, scrubbing the gases with an absorption oil to absorb light condensible fractions of the former in the latter, re-

moving the flash residuum from the cracking operation, mixing the enriched absorption oil with a quantity of the residuum suflicient in amount and temperature to vaporize the absorbed condensible fractions while retaining a substantial portion of the absorption oil in admixture with the residuum, and recovering the resultant blend of absorption oil and residuum as a product of the process.

3. In the cracking of hydrocarbon oils for the production of gasoline wherein pressure on the oil is lowered after heating to cracking temperature and wherein incondensible gases and a liquid residuum are formed as by-products, the method which comprises separating the gases from the gasoline and scrubbing the same with an absorption oil to absorb light condensible fractionsof the former in the latter, removing the residuum from the cracking operation, mixing the enriched absorption oil with a quantity of the residuum sumcient in amount and temperature to vaporize the absorbed condensible fractions while retaining a substantial portion of theabsorption oil in admixture with the residuum, and recovering the resultant blend of absorption oil and residuum as a product of the process.

JAMES M. WADSWORTH. 

